The invention relates to a self-service checkout for acquiring data from merchandise.
Products in the commercial environment are usually marked with barcodes which are normally applied to the packaging or the product itself by the manufacturer. In order to read a barcode, use is made of barcode readers, which are available in different forms for the various areas of use. The most common readers contain a laser and various mirrors in order to scan the barcode pattern. There are barcode readers which are permanently installed and portable barcode readers.
However, in addition to barcode technology, RFID (“radio frequency identification”) systems are also increasingly being used as identification marks and are utilized to identify products.
An RFID system essentially comprises two components: the mobile data storage media, which are also referred to as an encoder, transponder, RFID tag, ID transmitter or ID card and are carried by a user or are fitted to an object to be identified such as a commercial product, and the reader, which is also referred to as a base station or transceiver and reads the data from the transponders or writes new data to the latter. In addition, the reader can also provide power for the transponder. An antenna which, in simple cases, is in the form of an air-core coil is needed at both ends to transmit the data. Depending on their design, the transponders store information which ranges from a simple identification number to complex user or measured data. In the case of transponders, a distinction is made between active and passive identification. Passive identification is distinguished by the fact that the transponder can be continuously checked by the reader without the assistance of the user or the product. They obtain their power from the reader's magnetic field. As a result, they are very robust and require no maintenance. If the encoder is within a certain range of the transmission and reception unit, identification is effected automatically. The range is generally restricted by the radio field attenuation. By contrast, in the case of an active identification system, communication is actively initiated by the user from the transponder. In this case, a user must operate the transponder manually. Active transponders have their own power source, usually in the form of a primary source. The limited life is disadvantageous here.
Various radio-based transmission technologies are possible or customary: LF systems in the frequency range of 100-300 kHz, RF systems at 433 MHz or 867 MHz and radio-frequency microwave systems, which usually operate at the frequencies of 2.4 GHz, 5.8 GHz, 9.5 GHz or 24 GHz. Transponders in the kHz frequency range have ranges of a few centimeters. They are referred to as proximity tags, since they operate in direct proximity. Transponders which operate in the MHz frequency range are called vicinity tags, since, with ranges of up to approximately 2 m, they are used in the vicinity of the registration devices. Active transponders having a range of up to several meters essentially operate at the frequency of 2.4 GHz.
These RFID systems are also increasingly being used in supermarkets, with the proximity transponders, in particular, being used in this case. In the commercial environment, in addition to identifying the commercial product, RFID tags of this type have the advantage of a considerable improvement in product tracking, thus making the logistical processes easier for the manufacturer to comprehend than is the case with a barcode. In particular, the transponders are resistant to environmental influences, for example high and low temperatures, moisture, vibration, impact, dust, oil and dirt. Depending on the design of the finished product, the transponder may be fitted discreetly or invisibly, for example in the packaging.
In the commercial environment, particularly in supermarkets, self-service checkouts are increasingly being used to lower the personnel costs. Various self-service checkouts are known, in the case of which the products selected by the customer are registered and an automatic bill is produced. The customer takes the products, which have normally been deposited in a shopping cart, to the self-service checkout and subjects them to a scanning operation in which the barcode on the products is normally scanned by a barcode reader. The products are then placed in a packing area which may also be a further shopping cart or a shopping bag and which is coupled to scales. When the products are being identified by scanning the barcode, the product price, the type of product and the weight are determined. When the customer then places the products in the packing area, they are weighed again and the weighing result is compared with the weight intended for this type of product or with the weight which was determined when recording the weight of products which had to be weighed individually. If the comparison variables match, incorrect evaluation or an attempt to deceive can be ruled out.
EP 338 376 A2 describes a method for optically scanning markings, such as barcodes, on articles at a self-service checkout.
If, however, products are now offered which in some cases are provided with a barcode identification mark and in other cases are provided with an RFID identification mark, the cashier (in the case of an attended cash register) identifies whether the product is provided with an RFID tag or with a barcode and can then use a barcode reader or an RFID reader according to the marking which has been applied. By contrast, in the self-service environment, it has hitherto not been possible to use the customary self-service checkouts to register these products which are identified using an RFID transponder.